hsv i vs hsv ii

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  • 7/30/2019 HSV I vs HSV II

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    HSV I and II:

    (8/17/2007)

    General Characteristics:

    Similarities between HSV-I and HSV-IILinear, double stranded DNA virus

    No known animal vector

    Humans are the natural reservoir

    50% homology of base sequence

    Similar glycoprotein surface antigens

    Direct contact with infected secretions is primary mode of transmission

    Transmission may occur while asymptomatic (i.e. virion have been isolated from saliva

    and genital secretions even when clinical symptoms were absent)

    Stress activated recurrences (mechanism not understood, but observed factors are light,

    fever, and trauma)

    Differences between HSV-I and HSV-II

    HSV-I HSV-II

    Glycoprotein gB1 Glycoprotein gB2

    Associated with transmission by non-

    sexual direct contact with infected fluid

    Associated with transmission by sexual

    contact (i.e. STD) with infected fluid

    Signs and Symptoms:

    HSV-I HSV-II

    Primary infection may be asymptomatic ormay be characterized by oral (fever)

    blisters, ocular lesions, encephalitis

    Primary infections may be asymptomaticand first clinical episode may not be

    observed for years after primary infection.

    Grouped or single vesicular lesions

    involving the ectoderm (skin, mouth,conjunctiva, nervous system)

    Lesions begin as small erythematous (red)

    papules which form vesicles. The vesiclesform pustules. Some heal without scarring

    On dry surfaces, lesions scab beforehealing. One mucosal surfaces, lesions re-

    epithelialize directly

    Genital and anal regions may be affectedwith lesions. Urethra and cervix may also

    be infected.

    After initial infection, virus becomes latentin sensory nerve root ganglia or trigeminal

    nerve.

    Signs and symptoms may also include:bilateral inguinal lymph nodes and

    systemic symptoms (fever, malaise,myalgia, aseptic meningitis)

    Recurrent infection signaled by tingling or

    buring in the area.

    More likely to recur than HSV-I

    Symptoms may last 7 days Recurrences are shorter with no systemic

    symptoms (though genital lesions do occur)

    May also infect fingers or nail area (called

    herpatic whitlow).

    Most recurrences occurs from reactivation

    of the virus from dorsal root ganglia

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